Power Quality is a combination of Voltage profile, Frequency profile, Harmonics contain and reliability of power supply. The Power Quality is defined as the degree to which the power supply approaches the ideal case of stable, uninterrupted, zero distortion and disturbance free supply.

CAUSES OF POOR POWER QUALITY:
Variation in voltage magnitude and frequency. Variation in magnitude can be due to sudden rise or fall of load , outages, repetitive varying loading pattern, power electronic converters, inverters, etc. Variation in frequency can rise of out of system dynamics or harmonics injection.

IMPACT OF POOR POWER QUALITY:
The effect of poor power quality problems has serious implication on the utilities and customers.

• Higher losses in transformers, cables .
• Power factor capacitors may puncture.
• Neutral wire burning due to third harmonics generated by non linear loads.
• Solid state protective relays may get damaged .
• Speed drives may shut down.
• Non sinusoidal waveforms will reduce the efficiency of motors.
• Electronic components may be damaged due to voltage variation .

To improve the power quality, Capacitor banks and Active filters are used.

Standard and Detuned Capacitor Banks
Active Filters

Standard and Detuned Capacitor Banks
Capacitor Banks improve the power factor by adding capacitive reactance in steps as per the power factor requirement.

Power factor controller constantly monitors the load and power factor of the system on LV Panel and switch on/off the capacitor steps to maintain the system power factor to the set value. It provides optimum power factor improvement to compensate for lagging VARs in the system, seen as a clean and reliable solution to providing quality power to the distribution network and to economize the electricity charge to customer/consumer.

Key features of Capacitor Banks offered by AGS

• Type tested assemblies for busbars as per IEC 61439-1
• Rated upto 800kVAR
• Power factor correction by multi step design
• Standard & detuned capacitor banks
• Manufactured to Form 2 construction
• Capacitors are dry type, Self-healing, with pressure sensitive disconnector & fitted with discharge resistors
• Detuned reactor tuning order 2.7 (135 Hz), 3.8 (190 Hz) and 4.3 (215 Hz)
• Microprocessor based power factor controller with various switching sequences
• Special contactors for power factor correction capacitors; equipped with limiting resistance for the inrush current.
• Easy installation & maintenance.

Active Filters
Active Harmonic Filters (AHF) are static power electronic products that employ digital logic and IGBT semiconduc- tors to synthesize a current waveform that is injected into the electrical network to cancel harmonic currents caused by nonlinear loads.

AHF employ current transformers to measure the load current to determine the content of harmonic current pres- ent. By injecting the synthesized current, network harmonic currents are greatly mitigated, thus reducing the heating effects of harmonic current and reducing voltage distortion to permit other equipment to operate prop- erly and enjoy a long product life span.

Key features of Active Filter Solutions offered by AGS

• Rated from 30A to 600A
• 3-Wire Active filters for networks with pre-dominantly Three Phase loads, like Panels feeding VFDs, UPS.
• 4-Wire Active filters for networks with pre-dominantly Single Phase loads, like panels feeding office areas
• having high concentration of electronic ballasts, computers, etc.
• Manufactured to Form 2 construction, up to IP-54
• Support for Harmonics measurement, Analysis, Selection & Commissioning.
• Easy installation & maintenance.